The invention relates to molding compounds (i.e., molding materials) for encapsulating semiconductor components. These compounds include an aromatic and/or heterocyclic polyepoxy resin, an aromatic polyamine as a hardener, and mineral fillers in powder form. The mineral fillers may be in a mixture with inorganic short fibers. The invention further relates to moldings (i.e., molded materials) made from such molding compounds.
Cross-linkable (i.e., hardenable) resin systems are of special importance for insulation technology, especially as resin matrices for molding compounds. Examples of such resin systems include epoxy resin molding compounds, especially those in the form of the reaction resin molding compounds Type 870 and Type 871 (see in this connection: H. Saechtling, "Kunststoff-Taschenbuch", 20th Edition, 1977, page 416 and Table 85), that is epoxy resin molding compounds (according to DIN 16912) with an inorganic granular or inorganic short-fiber filler.
While the epoxy resin molding compounds, especially those with aminic hardeners of the aromatic amine type such as 4,4'-diaminodiphenyl-sulfone (see, for instance, DE-OS No. 32 10 746) furnish high quality moldings in the cross-linked state, they have only limited storage stability. These molding compounds do not permit adjustment of a state with stationary properties, due to the continuously progressing reaction between the epoxy resin and the amine which progresses rapidly even at low temperatures. Furthermore, the continuously progressing chemical reaction between the epoxy group and the amine hydrogen causes a corresponding change of the processing parameters and may also influence the quality of the moldings produced from the molding compounds.
Molded materials with high dimensional stability under heat can be made from polyepoxy resins (i.e., polyglycidyl compounds) and polyamines with isocyanurate structure elements, such as known from German Pat. No. 27 43 680. However, it is apparent that there is a problem of limited processability with respect to such molding compounds.
It is, therefore, an object of the invention to develop storage stable molding compounds for encapsulating semiconductor components which compounds include a polyepoxy resin and a polyamine as a hardener. It is a further object of the invention to develop storage molding compounds which ensure that moldings manufactured therefrom meet the requirements desired of these materials.